Sampling Toronto’s waters for microplastics

On June 19th, biologist Lisa Erdle, in collaboration with Toronto Brigantine Inc., officially launched a microplastics monitoring program for Toronto and the Great Lakes. Lake Ontario Waterkeeper had the honour of accompanying the team on the program’s first official sample sail.

On board the Toronto Brigantine tall ship TS Playfair, we sampled Toronto’s inner harbour as well as Humber Bay for microplastics.

Master Patrick Shore, who manages the microplastics testing program this summer on the TS Playfair, lowers the net. (Photo via Lake Ontario Waterkeeper)

One of the most important goals of Erdle’s microplastics survey is to help quantify the amount of microplastics in the Great Lakes, and specifically in Toronto’s waters. Following the launch of the program, Toronto Brigantine Inc.’s tall ships, the TS Playfair and STV Pathfinder, set sail with their young crews to travel through the Great Lakes. The crews have been gathering microplastic samples from Lake Huron and the North Channel, Lake St. Claire, Lake Erie, and Lake Ontario.

Since June, Erdle has also continued to collect regular samples in Humber Bay and Toronto’s Inner Harbour. Ashbridges Bay will also be surveyed over the course of the summer. These sites were specifically chosen as sampling locations as they are hot spots for Toronto’s effluent.

Every sample that Erdle collected this summer has contained microplastics.

The program will run the length of the sailing season and is due to wrap up around Thanksgiving.

Locally, the monitoring program is meant to raise awareness about the quantity of plastics in Toronto’s waters. Getting Toronto to connect the abundance of plastics in the city’s waters to the plastics it flushes down the drain or doesn’t dispose of properly is paramount. The survey of microplastics in Toronto’s waters is the first of its kind.

What are microplastics?

Once in the water plastics never biodegrade. Plastics break down to smaller and smaller pieces, but they don’t ever disappear from the ecosystem. Microplastics are defined as plastic particles that are less than five millimetres in size; so small they are hard to see with the naked eye. Primary microplastics, like microbeads and nurdles, are intentionally manufactured to be small. Secondary microplastics are fragments of larger plastic objects.

The impact of plastic objects and large plastic fragments on the environment is well documented. We’ve all had our hearts wrenched by images of marine animals entangled in six-pack rings and drift nets, or of the fate of sea turtles and albatrosses that mistakenly consumed plastic bags and toys as food. However, we are only beginning to understand the impact of microplastics on marine life and on the marine environment.

Plastic particles often act like sponges for contaminants and are therefore extremely toxic.

The latest research has confirmed that microplastics are being consumed by everything from zooplankton, corals, and fish larvae up the food chain to include large marine mammals and humans. In the digestive system, microplastics can cause blockages, malnutrition, starvation and eventually death. Unraveling the effects of the microplastics as work their way up the trophic levels is a brand new area of study.

The full impact that consumption of and exposure to microplastics is having on aquatic environment is not yet known. There is, however, enough research to paint a very dire picture of what the continued and increased presence of microplastics means for the future of our fresh and marine waters.

All streams run to the sea… And they are full of plastic

Lisa Erdle is many things: a sailor, a biologist, an educator, a restorer of waterways and aquatic habitats, and dedicated and innovative researcher. In short, Erdle is a water leader. She’s a mover and a shaker, and she’s doing the groundwork needed to ensure a healthy future for our waterways.

Her microplastics testing program was inspired by all the worlds she works in.

Lisa Erdle currently works as a biologist for Ontario Streams, an Aurora-based non-profit dedicated to restoring and preserving creeks and streams in Ontario. Her field work brought Toronto’s plastic pollution to her attention. Trudging through Toronto’s creeks and along the banks of the city’s rivers Erdle has seen with her own eyes what all the research on plastic pollution has concluded: the vast majority of plastics (upwards of 80%) found in our waterways is coming from the land.

Erdle saw a lot of plastic in Toronto’s rivers and creeks. Originating from both litter and wastewater, she followed its course downstream to Lake Ontario.

Erdle sailed with Toronto Brigantine’s youth program and saw an opportunity to give back to the program that she had gained so much from with her microplastics research. Microplastics testing is now part of Toronto Brigantine Inc.’s youth sailing program. The monitoring program engages the young sailors in science while at the same time contributes pertinent data to the survey of microplastics in the Great Lakes.

Microplastics in the Great Lakes

Erdle’s program is contributing to the larger body of research by the State University of New York at Fredonia (SUNY Fredonia) on plastic pollution within freshwater ecosystems of the Laurentian Great Lakes. In 2012, Dr. Sherri Mason of SUNY Fredonia headed the first ever microplastics survey on the Great Lakes in collaboration with the 5 Gyres Institutes. Findings from the study estimated prevalence of microplastics in the Great Lakes to be an average of 43,000 microplastic particles per square kilometer.

The 2012 survey found the highest abundance of microplastics were around urban centres (two samples from urban sites in Lake Erie measures 466,000 particles/km2.)

While microplastics can’t be removed from the water, cutting off the flow of plastics into the water will at least stop the problem from getting worse.

That is why Erdle’s microplastic program is so important. Her hope is that her work with Toronto Brigantine’s young crew will raise awareness to the quantity of plastics in Toronto’s waters and throughout the Great Lakes. Quantifying the number plastics in our waters, pinpointing the sources of the plastics that are making their way into our waters all contribute to stopping plastic pollution.

Microplastics sampling 101

Erdle’s microplastics testing program is completely volunteer run and all the equipment used is either lent or donated.

Microplastic testing is conducted using a very fine mesh net, typically a neuston net. The net is lowered into the water and towed at the water’s surface at a defined depth. The net is towed for a set amount of time.

Debris, both natural and plastic, is collected at the bottom of the net in a sieve.

Lisa’s program is using Mason’s neuston net to collect samples. The collections are then sent to SUNY Fredonia for analysis.

In the lab, natural debris is sorted from the plastic debris. The plastics are counted, weighed, and categorized.

Using this data – the dimensions of the sample tow, the number of pieces collected per km2, and the weight (g km2) of the microplastics collected – the density of microplastics can be estimated.